1. Field of the Invention
The present invention relates to a paper cassette that may be installed in a printer, and more particularly, to a paper supply cassette to supply paper loaded therein to the printer by receiving a driving force from the printer.
2. Description of the Related Art
In general, a printer has a paper supply device which contains and supplies paper to a printing portion. Paper supply devices can be classified into multi-purpose paper supply devices integrally placed within the printer, and paper supply cassettes. In particular, a large capacity printer is typically designed to be capable of using one or more paper supply cassettes.
When the paper supply cassette is installed in the printer, it is common that a driving apparatus to supply paper is provided at the printer while only the cassette containing paper is installed to slide into/from the printer. However, when the paper supply cassette is to be optionally installed in the printer, a driving motor is separately installed at the paper supply cassette or the paper supply cassette is driven by a gear connection mechanism with the printer.
FIG. 1 is a view illustrating a conventional printer having a paper supply cassette. As shown in FIG. 1, a paper supply cassette 110 is coupled at a lower portion of a printer 100. A drive gear 120 meshed with a driving motor (not shown) is provided at the lower portion of the printer 100.
The paper supply cassette 110 includes a main body 130 coupled to the printer 100 and a container 170 where paper S is loaded. The container 170 is coupled to the main body 130 to slide along the direction A of FIG. 1.
In the main body 130, there is a paper supply roller 140 to supply the paper S to the printer 100 while rotating in contact with the paper S loaded in the container 170, and a driven gear 150 engaged with the drive gear 120 and to transfer a rotational force of the drive gear 120 to the paper supply roller 140.
When the paper supply cassette 110 is coupled to the lower portion of the printer 100, since the drive gear 120 and the driven gear 150 are meshed with each other to transmit power, the rotational force of the drive gear 120 is transferred to the paper supply roller 140 via the driven gear 150. Thus, when the drive gear 120 rotates, the paper supply roller 140 rotates so that the paper S loaded in the container 170 is supplied to the printer 100.
The printer 100 may use only a paper supply cassette (not shown) installed within the printer or a multi-purpose paper supply device 160, without additionally installing the paper supply cassette 110. Thus, the drive gear 120 to transmit power to the additionally installed paper supply cassette 110 is typically installed inside the printer 100 to be separated a predetermined distance upward from the lower surface of the printer 100. This is because, if the drive gear 120 is installed to protrude downward from the lower surface of the printer 100, the drive gear 120 can interfere with a table (not shown) when the printer 100 is placed on the table for use. Thus, for the driven gear 150 installed at the main body 130 of the paper supply cassette 110 to be engaged with the drive gear 120, the driven gear 150 should be installed to protrude a predetermined height upward from the upper surface of the paper supply cassette 110.
When the driven gear 150 protrudes upward from the upper surface of the paper supply cassette 110, careful attention is needed when the paper supply cassette 110 is carried or installed at the printer 100. This is because a tooth profile of the driven gear 150 may be damaged or a gear shaft can be bent by an external impact. Such a damaged tooth profile or deformed gear shaft may cause noise during the supply of paper, or malfunction of the paper supply. Furthermore, in some cases, connection with the drive gear 120 is not possible.